Descenson device

ABSTRACT

A device for carrying personnel from one level to a lower level, the device being automatically returnable to the upper point. The device includes an upstanding support, a carrier for vertically traversing the support, a sheave secured at the upper end of the support, a counterweight disposed within the support member for vertical movement, a cable engaging the sheave and being secured at one end to the carrier and at the other end to the counterweight within the support, and a braking system mounted on the carrier to stop the carrier in an emergency. Also provided is a pressurized fluid system to expedite return of the carrier to the upper point for re-use or to support a load in the ascending operation.

United States Patent 1191 Allen 1 Oct. 16, 1973 DESCENSON DEVICE [57] ABSTRACT [76] Inventor: Marion F.Allen,P .().o x 3387, s% tm a. .i w ,2 1 n OdessaTex A device for carrying personnel from one level to a lower level, the device being automatically returnable [22] Ffled' 1972 to the upper point. The device includes an upstanding [21] Appl. No.: 239,127 support, a carrier for vertically traversing the support, 1 tr r a, H a a sheave secured at the upper end of the support, a 52 US. 01. 182/146, 182/229 counterweight disposed within the pp member [51] Int. Cl. E04g l/18 for vertical movement, a cable engaging the sheave [58] Field of Search 182/146, 145, 100, and being secured at one end to the carrier and at the 1 2/ 2, 229 other end to the counterweight within the support, I and a braking system mounted on the carrier to stop [56] References cued the carrier in an emergency. Also provided is a pres- UNITED STATES PATENTS surized fluid system to expedite return of the carrier to 2,549,707 4/1951 Plummer 182/82 the pp Point for re-use Or to pp a load in the 182,380 9/1876 Miller 182/146 ascending operation. 3,146,855 9/1964 Aberegg 182/146 Primary Examiner-Reinaldo P. Machado Attorney-James F. Weiler et al.

11 Claims, 4 Drawing Figures PATENTEU UN 18 I975 SHEET 10F 2 BACKGROUND OF THE INVENTION In the drilling of oil and gas wells as in many types of construction, it is necessary to transport personnel to and from elevated levels. Stairs, elevators and the like are required which in many instances are not only time consuming but result in wasted motion. Particularly in the drilling of oil and gas wells is there danger of blowouts, explosions, fires and other perils necessitating quick evacuation from working structures. Consequently, it would be most advantageous to provide a means of descent from such structures that is reliable, safe, fast and relatively free of mechanical problems.

It further would be advantageous to provide a means not only for rapid descent but also for expeditious ascent from one level to a higher level. The present invention is directed to such means.

Applicant is presently aware of existing patents in the field of art including US. Pat. Nos. 1,069,740 (Sweeney, 1913); 2,375,104 (Heitshu, 1945); 2,549,707 (Plumm'er, 1951); 2,965,193 (Murphy, 1960); and 3,255,845 (Gardner, 1966).

SUMMARY OF THEPRESENT INVENTION The ascendable descension device of the present invention generally comprises an elongate, upstanding hollow support member, a carrier for vertically traversing the support member, a sheave secured to the upper end of the support member, a counterweight disposed within the support for vertical movement, a cable about the sheave, one end of the cable being secured to the carrier and the other being secured to the counterweight, and braking means mounted on the carrier for bringing the carrier to a stationary position in an emergency such as upon severance of the cable. Preferably, the hollow support member is sealed so as to contain a fluid and is provided with a conduit providing fluid communication between the ends of the support member so as to regulate movement of the counterweight for purposes both of descending and ascending operation of the device.

It is, therefore, an object of the present invention to provide a descension device providing a means of quick descent from an upper to a lower level wherein the carrier portion of the device may return automatically to the upper position for further use.

Another object of the present invention is to provide a descension device that may be installed readily while at the same time being easily dismantled for relocation for further use. I

Yet a further object of the present invention is the provision of an ascendable descensio device of the type described wherein the carrier poi tion of the device may be raised with a load from one point to a higher point by means of a pressurized fluid system.

A still further object of the present invention is the provision of a descension device wherein the rate of descent may be adjusted readily to regulate the speed of descent based on the weight of the personnel or other load being transported.

Other and further objects, features and advantages will be apparent from the following description of pre ferred embodiments of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the drawings forming a part of the disclosure herein, like character references designate like parts throughout the several views, wherein FIG. 1 is a side elevation view of the descension device according to the present invention,

FIG. 2 is a front elevation view of the device, taken along the line 2-2 of FIG. 1,

FIG. 3 is a partial cross-sectional view of the device taken along the line 33 of FIG. 1, and

FIG. 4 is a partial schematic view of a system for lifting the carrier portion of the device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The descension device 10 of the present invention includes an elongate, upstanding enclosed hollow support member 12 preferably tubular or cylindrical in shape although other configurations may be used. Mounted at the upper end of the support member 12 is a sheave 14 oriented in the vertical plane. The sheave 14 is secured to a block 16 that in turn is securely mounted to the upper end of the support member 12.

As shown in FIG. 1, a counterweight means 18 is disposed within the hollow support member-l2 for vertical movement therewithin. The counterweight means 18 includes a body portion 20 having swabs 22 at both ends. The swabs 22 are secured to the body portion 20 by means of jam nuts 24.

A cable 26 passes into the upper end of the support member 12 so that one end of the cable is secured to the counterweight means 18 while the other end is secured to a carrier means 28. Preferably, the support member 12 is provided at its upper end with a suitable stuffing box 30 for slidably yet sealably receiving the cable 26 passing into the upper end of the support member.

With reference to FIGS. 1, 2 and 3, the carrier means 28 is constructed so as to accommodate at least one person. The carrier includes a floor 32 preferably formed of skid-proof steel. The floor 32 is anchored to a plurality of braces 34 which in turn are secured to a cross brace 36. Rollers 38 are rotatably mounted on the yokes.40, the yokes encircling without contacting the support member 12. As will be explained hereafter, the rollers 38 on one side of the support member straddle a circulating line 42, these rollers being designated with reference numeral 38a. Hence the rollers 38 and 38a contact the exterior surface of the support member 12 to roll along the surface of the support member in the vertical direction. The rollers 38a are cut away at the center 44 (FIG. 3) in order to straddle and clear the circulating line 42.

With reference to FIG. 1, integral with the carrier means 28 is a braking means 46 mounted on the carrier means and coacting with the cable 26 such that slack in or severance of the cable engages the braking means with the support member 12 to bring the carrier means 28 to a stationary position with respect to the support member. The braking means 46 includes a pair of arms 48 (only one arm 48 being shown in FIG. 1, the other being hidden directly behind that shown) rigidly mounted to the upper yoke 40 of the carrier means 28. The arms 48 may be secured to the yoke 40 such as by welding, suitable bolts, etc. Pivotally secured to the arms 48 such as by means of an appropriate bolt 50 or fulcrum pin is a control lever 52 to which the cable 26 is securely connected. At the inward end of the control lever 52 is rigidly mounted a shoe 54 or friction plate constructed of friction material at its inner surface so as to stop movement of the carrier means 28 upon engagement of the friction surface of the shoe 54 with the surface of the support member 12.

In order to prevent undue pivoting of the control lever 52, stop members 56 are securely attached between the arms 48 so as to limit movement of the control lever as shown in FIG. 1. Thus, weight of the carrier means 28 as well as any load thereon causes the control lever 52 to pull against the cable 26 moving the control lever 52 into engagement with the stop members 56. This configuration normally remains the same throughout operation of the descension device 10. However, a spring 58 is connected at one end to the yoke 40 and at the other end to the control lever 52 pposite the fulcrum pin 50 from the cable 26 so as to bias the brake shoe 54 into a braking position with the support member 12 should the cable 26 ever become slack or severed or should operation of the counterweight means 18 ever malfunction.

With reference to FIG. 1, the circulating line 42 is a conduit secured along substantially the length of the support member 12 so as to provide fluid communication between the ends of the support member. Thus, the conduit 42 is connected at its tipper end to the upper end of the support member 12 and at its lower end to the lower end of the support member 12. Advantageously, and for reasons to be discussed hereafter, a valve 60 or other suitable restriction may be provided in the conduit 42 to slow movement of fluid therethrough. As mentioned previously, the support member 12 is enclosed so as to seal fluid there within. A line 62 with a valve 64 is provided at the bottom of the support member 12 for purposes of, for example, adding or drawing off fluid from within the support member as well as removing condensed moisture, etc. that might collect within the support member 12.

With respect to fluid used within thesupport member 12 and circulating line 42, such fluid may be air or other gas, a low viscosity oil, a suitable hydraulic fluid or other desired substance. In any event, it is desirable that the swabs 22 of the counterweight means 18 be in intimate contact with the interior wall of the support member 12 and that such wall be as smooth as possible for ease of slidability of the counterweight means 18 within the support member 12.

It will now be recognized that fluid within the support member 12 whether liquid or gas will; slow movement of the counterweight means 18. Thus, downward movement of the carrier means 28 will pull the cable 26 which in turn pulls thecounterweigl' lt means 18 upward. Consequently, the counterweight means 18 tends to compress the fluid and is slowed by the resistance created by virtue of the compressive effect. The compression or resistance to fluid flow may be increased by either decreasing the size of the conduit 42 or by closing down on the valve 60 within the cbnduit. Alternatively, the body portion 20 of the counterweight means 18 may be provided with an axial aperture acting as an orifice to obviate the necessity of the conduit 42 thereby enabling the fluid within the support member 12 to flow past the counterweight means. It further will be recognized that the valve 60 may be replaced by an orifice plate of a suitable size to regulate flow of fluid through the conduit or circulating line 42 as desired to limit the downward speed of the carrier means 28.

As shown in FIGS. 1 and 2, bumper means are provided to cushion movement of the carrier means 28 at the upper and lower extremities of its travel along the support means 12. The bumper means includes compression springs 66 mounted to the base of the support member 12 and compression springs 68 mounted at the upper end of the support member. The carrier means 28 itself has attached thereto cups 70 at the upper end to engage the compression springs 68 and cups 72 at its lower end to engage the compression springs 66.

With reference to FIG. 4 of the drawings, a further embodiment of the invention is shown relating generally to a pump circuit for means of pumping fluid within the circulating line or conduit 42 and the support member 12 in order to move the carrier means 28 upward with a load. At the same time, the pumping circuitry is such that the pump means may be by-passed so that the fluid circulates between the conduit 42 and the support member 12 as discussed heretofore.

In the schematic of FIG. 4, the conduit 42 is piped to a four-way valve 80. Also piped to the four-way valve is a pump 82 (which may be a compressor if air or other gas is the fluid used within the system) with a suction line 84 drawing from a reservoir 86. Feeding into the reservoir is a pipe 88 connected to a three-way valve 90. One leg of the three-way valve 90 is piped to the four-way valve 80 while another leg 92 is piped to the bottom or return portion 42a of the conduit 42. The conduit 42a is provided with an extension 42b for connection to the four-way valve 80. When operated as will be explained, the system of FIG. 4 serves to pump fluid from the reservoir 86 into the circulating line 42 to the top of the support member 12 to force the counterweight means 18 (functioning as a piston) downward through the interior of the support member. The downward movement of the counterweight means 18 forces fluid out of the support member 12 and into the return line 42a and its extension 42b, through the fourway valve 80 as shown, through the three-way valve 90 as shown, into the conduit 88 and thence back into the reservoir 86.

On the other hand, if the carrier means 28 is to be lowered, the pump 82 is shut off so as to provide resistance of flow offluid backwards through the pump, and the plug portion 81 of the four-way valve 80 is rotated 90 so that the conduit 42 communicates directly with the three-way valve 90. The three-way valve 90 is then rotated 90 counterclockwise from the position shown so that the conduit 42 is then in direct communication with the return line 42a. The system then functions as described previously with respect to FIGS. 1-3.

In operation and with respect first to FIGS. l-3, the descension device 10 of the present invention is erected adjacent to a structure to or from which quick egress or ingress is desired. For example, the working floor of an oil well derrick may be represented for purposes of illustration as the working level 94 shown in FIGS. 1 and 2. In erecting the descension device 10, the support member 12 is anchored in a suitable manner to the ground or other base 96 and the upper end of the support member is secured by means of brace legs 98. The brace legs may be fastened to the support member 12 such as by means of a suitable yoke 100 and may be fastened to the working floor 94 such as by bolting, etc.

The counterweight means 18 should be at least as heavy as the combined weight of the carrier means 28 and the braking means 46 attached to the carrier means. Preferably, the counterweight means 18 including swabs 22 and the jam nuts 24 weighs approximately 60 to 80 pounds more than the carriage means 28 and associated braking means 46 under no-load conditions. Under these circumstances, and with use of air as the fluid within the circulating line 42 and the support member 12, it has been found that a 200 pound man can be lowered 30 feet by the device of the present invention in 6 seconds.

The weight of the counterweight means 18 acting against the cable 26 pulls the carrier means 28 into contact with the compression springs 68 so that the floor 32 of the carrier means 28 is approximately even with the working level 94 of the adjacent structure. At this point, a person may step onto the floor 32 of the carrier means 28 and descend to the ground or base level 96 when the lower end of the carrier means 28 engages the compression springs 66. In so doing, the counterweight means 18 is pulled upward by the cable 26. In its upward travel, the counterweight means 18 acts as a piston to compress air ahead of it thereby slowing the downward movement of the carrier means 28. As stated previously, the body portion 20 of the counterweight means 18 may include an axial aperture acting as an orifice to permit the escape of air or other fluid from one side of the counterweight to the other. However, as shown in FIGS. 1 and 2, and as is pre ferred, a conduit'or circulating line 42 is provided so that fluid may communicate from one end of the support member 12 to the other, i.e., from one side of the counterweight means 18 to the other. Also, a valve 60 may be provided to regulate the rate of flow of fluid through the circulating line 42 or an orifice plate may be added in place of the valve 60 or the circulating line 42 may be sized so as to itself act as an orifice. An advantage of use of the valve 60 is that the rate of fluid flow through the circulating line 42 may be regulated for different load weights. For example, a very heavy person would find it desirable to close down on the valve 60 to provide more restriction in the circulating line 42 while a lighter person would want to open the valve 60 to increase the flow through the line 42.

If a hydraulic fluid is used in lieu of air or other gas within the circulating line 42 and support member 12, the same operational steps are employed as previously described. However, it will be recognized, of course, that liquids are not compressible in relation to air or gases and speed of movement of the carrier means 28 as well as the counterweight means 18 lwill be different depending on viscosity of the liquid, temperature and the like.

In the event that the cable 26 should become severed or the swabs 22 should suffer unexpected wear or a leak develop within the conduit 42 or support member 12, then rapid and uncontrolled downward movement of the carrier means 28 is limited by the brake means 46. Braking action occurs due to slack, in the cable 26 or severance thereof such that the spring 58 pulls the control lever 52 toward the support member 12 so as to engage the friction surface of the shoe 54 with the outer surface of the support member 12. This frictional contact will bring the carrier means 28 to a stationary position thereby preventing injury to a person standing on the floor 32 of the carrier means or preventing damage to any other load that may be placed on the carrier means.

With reference to operation of the embodiment shown in FIG. 4 of the drawings, the system shown enables loads to be moved on the carrier means from the ground or base position 96 to a higher level (such as the work level 94 in FIGS. 1 and 2). In the schematic shown, it is assumed that a hydraulic fluid is used in the system and is moved by a suitable pump 82. It will be understood, of course, that air may also be used as the motive fluid in which case a compressor may be substituted for the pump 82.

Continuing with respect to FIG. 4, assuming that the carrier means 28 (of FIG. 1) is at ground or base level 96 and a load is to be raised to a higher point, the pump 82 is actuated thereby pumping fluid from the reservoir 86 (if air is used the reservoir 86 would be an air tank) into the circulating line 42 via the four-way valve 80. The fluid in the line 42 would then pass into the top of the support member 12 forcing the counterweight means 18 downward, the counterweight means 18 in effect acting as a piston. The downward movement of the counterweight means 18 would act on the cable 26 to pull the support means 28 upward thereby lifting the load. Fluid below the counterweight means 18 is returned to the reservoir 86 via the return line 42a and its extension comprising the line 42b and the piping leg 88. In the latter instance, of course, the valves and are in the configuration shown in the drawings to provide the stated fluid communication.

When the carrier means is at an upper level and it is desired to descend to a lower level, the plug portion 81 of the four-way valve 80 is rotated ninety degrees from the position shown in FIG. 4 and the three-way valve 90 is rotated counterclockwise ninety degrees from the position shown. It will be understood, of course, that operation of these valves may be controlled remotely by electrical circuitry or other suitable means. The pump 82 is shut off to provide resistance to flow of fluid from the suction line 84 into the reservoir 86 and the load may descend on the carrier means. During the descent, the counterweight means 18 forces fluid upward through the support member 12 and into the top of the circulating line 42. The fluid then passes downward through the circulating line 42, into the pipe 92 and back through the return portion 42a of the conduit into the support member 12. This schematic flow functions in the same manner as previously explained with respect to the operation of FIGS. 1-3.

Thus provided is a unique system of apparatus for moving persons or other loads from one elevation to another. The device is particularly useful as a rapid means of descension whereby the carrier means may automatically return to an elevated point of origin for further use. Furthermore, pumping or compressor circuitry with appropriate valving may be added to use the descension device for ascension purposes thereby enhancing overall utility of the system.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While a presently preferred embodiment of the invention has been given for the purpose of disclosure, numerous changes in the detail of construction and the combination, shape, size and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

l. A descension device including,

a. an upstanding, enclosed tubular support member provided at its upper end with a stuffing box means for slidably and sealably receiving a cable passing into the upper end of the support member,

b. a conduit substantially the length of the support member (a) and providing fluid communication between the ends of the support member,

0. carrier means for vertically traversing the exterior of the support member (a),

d. a sheave secured in the vertical plane to the upper end of the support member (a),

e. counterweight means disposed within the support member (a) for vertical movement therewithin,

f. a cable coacting with the sheave (d), one end of the cable being secured to the carrier means and the other end of the cable passing through the stuffing box means of the support member (a) and secured to the counterweight means (e),

g. braking means mounted on the carrier means (0) and coacting with the cable (f) such that slacking or severance of the cable engages the braking means with the support member (a) to bring the carrier means (b) to a stationary position with respect to the support member (a), and

h. fluid contained within the support member (a) and conduit (b) for slowing movement of the counterweight (e) within the support member (a).

2. The descension device of claim 1 wherein the fluid (h) is air.

3. The descension device of claim 1 wherein the fluid (h) is a hydraulic fluid.

4. The descension device of claim 1 wherein the counterweight means (e) is at least as heavy as the combined weight of the carrier means (c) and the braking means (g).

5. The descension device of claim 1 wherein more particularly the braking means (g) comprises,

i. a control lever mounted on the carrier means (c) so as to pivot in the vertical plane, the control lever serving to secure the cable (f) to the carrier means (c) by attachment of the cable to one end of the control lever,

ii. a friction plate secured to the other end of the control lever in juxtaposition to the support member (a), and

iii. spring means secured between the carrier means (c) and the control lever (i) so as to bias the friction plate (ii) toward the support member (a) and into intimate contact therewith upon slacking or severance of the cable (f).

6. The descension device of claim 1 including additionally a restriction in either of the upper extremity of the tubular support member (a) or the conduit (b) for restricting flow of fluid therethrough to in turn slow movement of the counterweight means (e) within the support member (a).

7. The descension device of claim 6 wherein the restriction comprises an orifice plate.

8. The descension device of claim 6 wherein the restriction comprises an adjustable valve.

9. The descension device of claim 1 including additionally bumper means mounted to the support member (a) for limiting vertical movement of the carrier means (c).

10. The descension device of claim 1 including additionally means coacting with the conduit (b) for forcing fluid (h) upward through the conduit and into the top portion of the support member (a) to in turn force the counterweight means (e) downward thereby elevating the carrier means (0).

11. The descension device of claim 10 wherein the fluid forcing means coacting with the conduit (b) includes,

i. means for pressurizing the fluid (h),

ii. a reservoir for maintaining an excess of the fluid (h), and

iii. piping and valving means coacting with the pressurizing means (i) and the reservoir (ii) for directing flow of the fluid (h) between the conduit (b) and the support member (a). 

1. A descension device including, a. an upstanding, enclosed tubular support member provided at its upper end with a stuffing box means for slidably and sealably receiving a cable passing into the upper end of the support member, b. a conduit substantially the length of the support member (a) and providing fluid communication between the ends of the support member, c. carrier means for vertically traversing the exterior of the support member (a), d. a sheave secured in the vertical plane to the upper end of the support member (a), e. counterweight means disposed within the support member (a) for vertical movement therewithin, f. a cable coacting with the sheave (d), one end of the cable being secured to the carrier means (c) and the other end of the cable passing through the stuffing box means of the support member (a) and secured to the counterweight means (e), g. braking means mounted on the carrier means (c) and coacting with the cable (f) such that slacking or severance of the cable engages the braking means with the support member (a) to bring the carrier means (b) to a stationary position with respect to the support member (a), and h. fluid contained within the support member (a) and conduit (b) for slowing movement of the counterweight (e) within the support member (a).
 2. The descension device of claim 1 wherein the fluid (h) is air.
 3. The descension device of claim 1 wherein the fluid (h) is a hydraulic fluid.
 4. The descension device of claim 1 wherein the counterweight means (e) is at least as heavy as the combined weight of the carrier means (c) and the braking means (g).
 5. The descension device of claim 1 wherein more particularly the braking means (g) comprises, i. a control lever mounted on the carrier means (c) so as to pivot in the vertical plane, the control lever serving to secure the cable (f) to the carrier means (c) by attachment of the cable to one end of the control lever, ii. a friction plate secured to the other end of the control lever in juxtaposition to the support member (a), and iii. spring means secured between the carrier means (c) and the contrOl lever (i) so as to bias the friction plate (ii) toward the support member (a) and into intimate contact therewith upon slacking or severance of the cable (f).
 6. The descension device of claim 1 including additionally a restriction in either of the upper extremity of the tubular support member (a) or the conduit (b) for restricting flow of fluid therethrough to in turn slow movement of the counterweight means (e) within the support member (a).
 7. The descension device of claim 6 wherein the restriction comprises an orifice plate.
 8. The descension device of claim 6 wherein the restriction comprises an adjustable valve.
 9. The descension device of claim 1 including additionally bumper means mounted to the support member (a) for limiting vertical movement of the carrier means (c).
 10. The descension device of claim 1 including additionally means coacting with the conduit (b) for forcing fluid (h) upward through the conduit and into the top portion of the support member (a) to in turn force the counterweight means (e) downward thereby elevating the carrier means (c).
 11. The descension device of claim 10 wherein the fluid forcing means coacting with the conduit (b) includes, i. means for pressurizing the fluid (h), ii. a reservoir for maintaining an excess of the fluid (h), and iii. piping and valving means coacting with the pressurizing means (i) and the reservoir (ii) for directing flow of the fluid (h) between the conduit (b) and the support member (a). 